What's more energy efficient...A Gas or Electric Range?
A frequent question I receive is if gas or electric stove-tops are more efficient. As with many of these questions, the answer is a very clear and concise...."Well, it depends."
Here's the summary...
First of all, let's establish three possible options (remember this is just for stove-tops, this is not a discussion about ovens):
2. Electric Resistance (coil that gets red hot, either beneath a glass top or as an exposed coil)
3. Electric Induction (newest option, not familiar to many - see my previous blog post about how these work)
Modernist Cuisine (an absolutely beautiful collection of books dedicated to the science of cooking by Nathan Myhrvold) analyzed the efficiency of these burners AT THE STOVE and came up with the following results. Efficiency here means the ratio of the energy that made it to the food divided by the energy that was delivered to the burner, either via electricity or gas. In other words, how effective was this burner at delivering the input energy to the food....
Efficiency at stove:
1. Gas = 30% efficient
2. Electric Resistance = 42% efficient
3. Electric Induction = 56% efficient
So - this appears to be an easy answer, right?? Obviously, electric induction is the most efficient. Well, not exactly. Even though gas is less efficient AT THE STOVE, it is important to remember that it started with a primary fuel (typically natural gas or propane). The electric options, on the other hand, started with a secondary "fuel" - electricity. In other words, we don't dig electricity out of the ground, it needs to be generated from another energy source.
Depending on where you live, that electricity may have been generated from a primary fuel (typically coal) at a power plant. Mosts traditional fossil fuel power plants are only about 33% efficient. So - if your electricity comes from a traditional fossil-fuel power plant (like is typical in the southeast US), about 2/3 of the available energy from the fuel has already been lost BEFORE it ever makes it to the stove. Taking this into account and calculating OVERALL efficiency, from primary fuel source to heated food, the picture changes significantly (remember this is assuming your electricity is generated from fossil fuels):
Overall efficiency from PRIMARY fuel source (assuming electricity comes from a traditional fossil fuel power generation plant):
1. Gas = 30% efficient
2. Electric Resistance = 15% efficient
3. Electric Induction = 20% efficient
Oh, so it appears that gas IS the most efficient now, right? Well - for me, living in North Carolina where most of my electric grid is supplied by fossil fuels, the answer is: yes, go for the gas (with reservation explained below).
BUT - if you live somewhere else in the country, say Washington state, where over 70% of the state's electricity is generated by non-fossil fuel hydro power, well, there is not a "primary fuel" in that case since the electricity comes not from a fossil fuel, but from the stored energy of water, and clearly the electric options use less fossil fuels.
To better understand how most of your state's electric generation is generated, visit the US Energy Information Administration (EIA) website. If you live in another country, research the energy grid in your area - this information is available online in many countries.
Add to this the complexity of small independent power production possibilities such as roof-top solar photo-voltaic panels which can generate electricity from the sun which makes the electric range options again look more attractive, even if the overall grid is powered primarily from fossil fuels.
There are other, non-thermal considerations to consider as well. For one, gas results in the products of combustion entering your living space. It is critical that you have a robust range exhaust air system to ensure those leave your living space and don't add to indoor air quality issues.
Also - gas and induction cooktops have the advantage of instantaneous response time. If your recipe requires a rapid change of burner temperature, these two options respond very quickly, electric resistance is more sluggish as the coil has significant thermal mass and will retain this high temperature even when the electric current delivered to the coil is reduced (when you turn the burner to a lower setting).
And then there comes the question of greenhouse gas generation. If you purchase a gas range, you are committing to the production of greenhouse gases (primarily CO2) whenever you fire up the burner. If we are envisioning a sustainable near-term future where much of our electric generation across the US is generated with renewable sources such as solar, wind and hydro, an electric cooktop allows our kitchen to adapt to this changing infrastructure and reduced greenhouse gas emissions.
My recommendation would be an electric induction cooktop as it's the most efficient electric-based option, does not emit products of combustion into your home, has very quick temperature response and allows for the reduction of greenhouse gases with our changing electric infrastructure.
Hey, I told you it wasn't an easy answer. Thanks for sticking with me through this explanation.
Remember - kitchens are a "no guilt zone." No matter what cooktop you choose, if you're using it and cooking delicious meals at home - you're dong great things!!